According to GB50303-2015 "Construction Quality Acceptance Specification for Electrical Engineering", when cable trays are laid parallel to thermal pipelines, the minimum clearance should be maintained at over 500mm; when crossing, it should be no less than 300mm. Cable tray (or cable ladder) systems are a popular alternative to electrical conduit systems, as they have an outstanding record for dependable service, design flexibility and cost savings in commercial and industrial applications. A properly designed and installed cable tray system will provide. 3) Replacing cables inside tray can be done in many cases without accessing the tray along it's full length. cables can usually (not always) be pulled from one end, or at least pulled through straight sections between tray elbows/tees without uncapping the whole tray. Not every area carries bulk power. ” In 1993 NEC Article 318 there are no requirements for the handling of the thermal contraction and expansion of cable tray.
